def is_boolean_true(value: str) -> bool:
    """Check if the value is 'true'."""
    return value.lower() == "true"

def is_boolean_false(value: str) -> bool:
    """Check if the value is 'false'."""
    return value.lower() == "false"

def is_null(value: str) -> bool:
    """Check if the value is 'null'."""
    return value.lower() == "null"

def is_number(value: str) -> bool:
    """Check if the value can be converted to a number."""
    try:
        float(value)  # Try to convert the value to a float
        return True
    except ValueError:
        return False
